Eukaryotes and Prokaryotes

Genome

Sum of all DNA molecules contained in each cell

Gene

Specific segments of DNA encoding structure + function info

Cell Theory

1. Cells are fundamental unit of life

2. All living organisms are composed of cells

3. All cells come from preexisting cells

4. Modern cells evolved from a common ancestor

Prokaryotes

Cell type. No membrane-bound internal structures. Bacteria + Archaea

Eukaryotes

Cell type. With membrane-bound organelles. Eukarya

Features in both prokaryotes + eukaryotes

1. Ribosomes (free ribosomes)

2. Cell membrane

3. Cytoplasm

4. Cytosol (liquid including ions, small molecules, biomolecules)

5. Biomolecules (Carbs, protein, lipids, nucleic acids)

6. Cytoskeleton

Cytoplasm

Everything inside cell membrane

Cytosol

Thick, water-based solution that is in cell membrane (contains biomolecules, ions, small molecules)

Cytoskeleton

gives shape to cell

Prokaryotic cells

• DNA located in nucleotide

• 1 circular chromosome

• Peptidoglycan in cell wall

• Cytoplasm

• Ribosomes

Nucleoid

Region not bound that contains DNA only in prokaryotic cells

Cell wall

Helps maintain size and shape of celll. Made of peptidoglycan (sugars + peptides)

Peptidoglycan

What makes up cell wall in bacteria. Sugar + peptides

Ribosomes

Site of protein synthesis

Eukaryotic cell

• DNA in nucleus

• DNA in multiple linear chromosomes

• Membrane-bound organelles

Chromatin

Histone proteins + DNA tightly coiled up. In eukaryotes.

Large surface area to volume ratio

Important for transport of resources and waste + communication between cells. Increased by smaller cell size + interesting shapes like folded RBC, micro ville in intestine, long neurons

Cell membrane

Phospholipid bilayer:

• Selectively permeable allowing cells to maintain a constant internal environment

• embedded proteins for binding/adhering to adjacent cells

• Important in communication and receiving signals

Organelles

Membrane-bound compartments for specialization in eukaryotic cells

Nucleus

• Site of DNA replication and gene transcription turning.

• Surrounded by nuclear envelope.

• Has nucleolus which is a region of ribosome assembly.

Nucleolus/Nucleoli

Region where ribosomes are made. In nucleus. Only in eukaryotes.

Central dogma

DNA — transcription —> RNA — translation —> Protein

Nuclear pores

Proteins are transported in and RNAs are transported out.

Mitochondria

Organelle where glucose is converted into ATP (cellular respiration). Unique organelles cause 1. Have their own DNA 2. Divide independently.

Endosymbiont theory

Explains mitochondria and chloroplasts for having their own DNA and dividing independently.

Mitochondrial matrix

Inside of mitochondria. Including DNA, ribosomes

Cristae

Folds of inner membrane of mitochondria

Endomembrane system

Network of membranes

Rough ER

ER with ribosomes. Newly made proteins enter RER lumen and get modified, folded, and transported.

Smooth ER

No ribosomes. Chemically modifies small molecules (drugs, pesticides). Synthesize lipids and steroids

Golgi apparatus

Receive proteins from RER, modifies, concentrates, packages, and sorts proteins before transporting.

Cisternae

Flattened sacs of golgi apparatus

Lysosomes

Vesicles that help digest macromolecules